# coding: utf-8
# Your code here!
TEMP=int(input())
if TEMP>=30:
    print("Yes")
else:
    print("No") TEMP=int(input()) TEMP int(input()) int input() input if TEMP>=30:
    print("Yes")
else:
    print("No") TEMP>=30 TEMP 30 print("Yes") print "Yes" print("No") print "No" TEMP=int(input()) int(input()) TEMP
# coding: utf-8
# Your code here!
TEMP=int(input())
if TEMP>=30:
    print("Yes")
else:
    print("No")